Speed responsive coupling



April 17, 1951 w. J. SPENGLER 2,549,749

SPEED RESPONSIVE COUPLING- Original Filed June 15, 1942 I- INVENTOR ATTORNEY Patented Apr. 17, 1951 UNITED STATES PATENT oFFlcE SPEED RESPONSIVE COUPLING Walter J. Spengler, Sidney, N. Y., assignor to Bendix Aviation Corporation, New York, N. Y., -a corporation of Delaware Original application June 15, 1942, Serial No.

447,104, now Patent No. 2,391,525, dated December 25, 1945. Divided and this application l. .lune 3, 1944, Serial No. 538,666

6 Claims. (Cl. (i4-25) -This invention relates to couplings and more particularly to means for connecting two rotating parts, such as parts of an internal combustion engine ignition system, so that automatic angular adjustments of said parts may be effected during rotation thereof, whereby the timing of the sparks produced by the ignition system in the engine cylinders may be automatically varied. Y

This application is a division of my copending application Ser. No. 447,104, filed June15. v1942, for improvements in Coupling Means," now Patent Number 2,391,525, issued December One of the objects of the present invention is to provide novel apparatus for mechanically coupling two rotating elements to each other while permitting of angular adjustment ofvone of said elements relative to the other.

Another object of the invention is to provide a novel automatic variable coupling for rotating parts which functions in accordance with the speed of rotation of said parts.

A further object is to provide novel means for automatically effecting adjustments in the timing of the ignition system of aninternal combustion engine.

Still another object is to provide novel coupling means of the above character v,whereby two rotating parts may be automatically angularly adjusted in one direction relative to each otherr at one speed of rotation and in the other direction'at a higher speed of rotation.

A still further object is to provideV a novel,

centrifugally responsive device for effecting an automatic variable connection between two rotatable'parts.

Another object is .to vprovide novel means adapted for use in the ignition system of an internal combustion engine for eiectingl spark some extent as a flexible coupling rto avoiddamf age which might otherwise be occasioned by sudden shocks and quick changes of speed. i

The above and further objects and novel features of the invention will more fullyappearMfrom the following detailed description when -thevsame is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only andare not intended as a definition of the limits of the invention, reference for this latter purpose being had primarily to the appended claims.

In the drawings, wherein like reference charf acters refer to like parts throughoutthe vseveral views, v

Fig. l is a side elevation of a magneto rotor., partly in section and with parts broken away., embodying one form of coupling unit comprehended by the present invention;

Fig. 2 is a side elevation, partly in section and with parts broken away, illustrating the novel coupling of Fig. 1;

Fig. 3 is'a detail plan view of said coupling unit, with'parts broken away to show structural details; Y

Fig. 4 is a detail view of apart of the coupling unit as seen from right to left inv Figs. 1 and 2;

Fig. 5 is a detail View showing one of the centrifugally responsive weight members of the coupling unit; and

Fig. 6 is an isometric view of a spring retainer used in carrying out Ythe invention.

Only one embodiment of the invention is illustrated in the drawings, by way of example, in the form of a coupling unit adapted for use in the ignitionL system of an internal combustion engine. As shown, the novel coupling unit of the invention is incorporated lin a magneto for the purpose of automatically varying the timing of the sparks in an ignition system relative to the positions of .the pistons in the engine in which the sparks occur.` The form of coupling unit shown is employed for connecting a rotating part of an engine (not shown) to the rotorv 52 in a magneto which may be of any suitable design well-known in the'art and, hence, is only partially shown. In a manner also well understood byV those skilled in the art, the rotor of the magneto is drivably connected with a circuit breaker cam (notshown) which operates in timed relation totherotor and determines the time of the occurrence of the sparks inthe engine cylinders. In a structure of this characf4 ter wherein' the timing cam is driven by the magneto rotor, the coupling unit of the present invention is preferably located so that the rotor and the cam are affected alike by adjustments made by said unit, thereby insuring the opening of the primary circuit of the magneto coil at the most advantageous moment for efficient operation irrespective of the adjustments effected by the coupling unit.

In the form shown, the novel coupling means is interposed between rotor 52, which includes a hollow shaft 53, and a composite shaft 54 comprising two coaxial parts fixed together by a pin 55. Either shaft 53 or 54 may be operatively connected to a prime mover, such as an internal combustion engine. For convenience in the description which follows, rotor 52', 53 will be referred to as a driven member and shaft 54 will be referred to as a driving member.

Shaft 54 and rotor 52, 53are operatively connected together by novel means including an axially movable intermediate torque transmitting member, such as sleeve 56. The latter is provided with internal splines at 51 and 58 which mesh, respectively, with external splines on shaft 54 and a projecting portion of rotor shaft 53,

the latter being journaled on a reduced end portion of driving shaft 54. Rotor 52 and shaft 54 may be rotatably supported in a housing and held against relative axial movement by suitable bearings (not shown). For a purpose to appear hereinafter, the splines of either one or both of the connections 51 and 56 are spiral in nature so that axial movement of sleeve 55 relative to shafts 53 and 54 will effect angular movement of rotor 52 relative to driving shaft 54. In the embodiment shown, splines 58 are straight and exa tend axially of the shaft, while splines 51 are spiral and mesh with spiral splines 59 on shaft 54.

Novel centrifugally responsive means are comprehended by this invention for completing the connecting means between shafts 53 and 54 and for effecting axial movement of sleeve 5-53 and, hence, relative angular movement of shafts 53 and 54 in accordance with the speed of rotation thereof, said means being effective to move said sleeve axially in one direction relative to said shafts when the parts are rotated at a predetermined speecl or within a predetermined range of speeds, and in the opposite direction when the parts are rotated at a predetermined higher speed l or within a predetermined range of higher speeds. I,

In the form shown, said centrifugally responsive means preferably comprise a plurality of systems of linked and pivoted weights combined with resilient means for opposing the centrifugal forces acting on the weights. Since the two weight systems shown are substantial duplicates, the only differences residing in reversals of parts, only one is hereinafter described in detail.

v The upper system of centrifugally responsive weights, as viewed in Figs. l and 2, comprises amain or principal weight 66 which is pivotally mounted on a flange 6I extending radially from and preferably integral with sleeve 56. lThe other end of weight 66 is pivotally connected to a pair of secondary or fly-weights 62, 53 that are, in turn, pivotally mounted on the end plate 64 of rotor 52. Weight 66 is pivotally supported on the adjacent inner ends of a pair of pivot or bearing pins 65 that threadedly engage spaced lugs E6 which are suitably secured, such as by riveting, to flange El. The inner reduced ends of pins 65 on which weight 60 is'journaled extend into a lateral opening 61 in said weight (Figs. 3 and 5). The surface of weight 6G that is adjacent sleeve 56 is preferably provided with a 4 recess 63 of semi-circular section (Fig. 5) for receiving said sleeve, which serves as a means for limiting the pivotal movement of said weight in a clockwise direction, as viewed in Figs. l and 2.

The two small arms or levers 52 and 63, which also act as centrifugal weights, are pivotally connected to opposite sides of weight 60 by being freely journaled on laterally extending pins 68 xed to said weight and are pivotally supported on the inner ends of pivot or bearing pins 1G, which are similar to pins 65, and threadedly engage spaced lugs 1I riveted onto rotor end plate 64. rThe above-described parts are so designed that the pivots 69 are normally spaced in the direction of the axis of rotation of sleeve 56 from the plane containing pivots 65 and 15 but will pass through said plane during movement of the connected ends of weights 6D, 62 and 63 in response to centrifugal forces during rotation of shafts 53 and 54.

The centrifugal weights are normally yieldably retained in the illustrated position by suitable resilient means and a novel combination of resilient means are provided for controlling 'the movement of said weights in response to centrifugal forces acting thereon during rotation of shafts 53 and 54 and sleeve 56. Although any suitable type of resilient means may be employed, a coil wire spring 12 is interposed under tension between a laterally extending grooved portion I3 of member 63 around pivot 69 and a retaining lmember 14 (Figs. 2 and 6) adjustably secured in place by pivot pins 16, 65. This spring normally holds weight 60 in its limiting position against sleeve 56 and begins to yield to the centrifugal force exerted by weights EG, 62 and 63 when the parts are rotated at a predetermined speed.

Depending upon the design of spring 12, the adjacent ends of centrifugal weights El), 62 and E3 connected by pins 6,9 may move out gradually from sleeve 56 as the speed of rotation of shaft 53, 54 increases above said predetermined speed or the same may move out rather promptly after said predetermined speed is attained. In either event, when the predetermind speed is reached or exceeded and the centrifugal weights have movd pivots 55 to a predetermined position, preferably into the plane of pivots 65 and 10, a second yieldable resisting' force, such as spring 15, comes into action and resists further movement of the weights as the speed and, hence, ,centrifugal force increases. .Spring 15, which is diametrically opposite spring 12 and identical withl spring 15 (Fig. 2), which will be referred toY hereinaftenis connected at one end to an adjustable retainer member 16 similar to member 14 and is provided at its other end with an elongated loop 11 which engages a groove in a lateral projection 18 of weight member 62. When, during the outwardfmovement of centrifugal weights 56, 62 and 63, the end of loop 11 is engaged by the projection 18, said outward movement will be slowed down or stopped, depending upon the design of the spring, until the speed of rotation of the parts reaches a predetermined higher speed. At this latter speed, spring 15 begins to yield and the weights move outwardly against the combined resistance of springs 12 and 15.

It will be seen that outward movement of the connected ends of weights 60, 52 and 63 from normal position will result in axial movement of sleeve 56 to the left, as viewed in the drawings, until pivots 69 move into the plane of pivots 65 and 10. Thereafter, continued-outward movethe ignition system embodying rotor 52.

kmove sleeve 56 to the right, this latter movement being limited by a shoulder 79 (Fig. l) on shaft 53, which is engageable by the end of said sleeve.'l

By reason of the spiral splines 5l, ,59 on sleeve 56 and shaft 54, axial movement of said sleeve in the above manner effects relative angular movements of said shaft and sleeve in different directions as the speed of rotation increases and, hence, similar relative angular movements of shafts 53 and 54. It will be understood that, as the speed of rotation is decreased, the reverse relative angular movements are eifected in response to the tension of springs 'I2 and 15. If the spiral splines 59 are properly chosen, the initial movement of the centrifugal weights at low speed will effect an advance of the spark setting of If the movement of the centrifugal weights is stopped by spring l5 whenpivots 69 are inline with pivots 65 and '10, the spark setting may be maintained `constant for a predetermined' range of speeds vand then automatically retarded at higher speeds as the weights move outwardly toward their limiting position and until sleeve 5S butts against shoulder '19.

The lower system of centrifugal weights, as viewed in the drawings, is the same as the upper system described above and operates in the same manner except that the positions of similar parts are reversed in the interest of compactness, the weight 60' being pivotally supported by end plate 64 and the yweights 62', 63 being pivotally supported by ange 5|. The corresponding parts of both weight systems are designated by the y same numerals except that those designating parts of the lower system are supplemented with a prime. It Will, of course, be understood that more or less than two systems of centrifugal weights may be employed.

If desired, the novel coupling unit of Fig. 1 may be enclosed by a cylindrical casing 80 which fits closely around end plate 64. One or more portions at the end of the casing may be pressed inwardly into engagement with fiattened portions of the periphery of said end plate and secured in place by set screws, as at 8l. The other end of casing 80 may be closed and centered about shaft 54 by a closure plate 82 which may be soldered in place in the casing.

There is thus provided novel coupling means for rotatable parts, such as a magneto rotor` and drive shaft therefor, whereby relative angular movements of said parts in either direction may be automatically effected during rotation thereof, and whereby relative angular movements in opposite directions may be elfected as the speed of rotation increases. Additionally, said coupling means are so constructed as to effect different relative angular movements of the connected parts at predetermined speeds thereof in response to centrifugal forces. The coupling unit provided may be employed in a novel manner to automatically control the spark setting of an ignition system in an infinite variety of ways for the purpose of obtaining eiiicient and economical operation at substantially all speeds. Furthermore, the novel coupling meansprovided are simple inconstruction and operation and are also compact and reliable.

Although only'one embodiment of the invention Vis illustrated and described in detail, it is to be expressly understood that the same is not limited thereto. As will now be apparent to those skilled in the art, various changes, such as in v drivably connecting said members including an element axially movable relative to said membersr vthe'design and arrangement of parts illustrated, may be made in the illustrated embodiment of the invention without departing from the spirit and scope thereof. For a definition of the limits of the invention, reference is had primarily to the appended claims.

What is claimed is:

l. Apparatus of the class described comprising two rotatable members adapted for angular Ymovement relative to each other, and means for drivably connecting said members including an element axially movable relative to both of said members and having a torque-transmitting connection with each of said members, said torquetransmitting connections being such that relative axial movement of one of said members and said element causes relative angular movement of said members, and centrifugally responsive means operatively connected to said element and to one of said members for moving said element axially rst in one direction and then` in the otherdirection relative to said members as the speed of rotation of the latter increases, said centrifugally responsive means comprising a pair of pivotally mounted and pivotally connected' weights, the extreme operating positions of the axis of said pivotal connection being on opposite sides of a plane containing the axes of said mounting pivots.

2. Apparatus of the class described comprising a rotatable member, a rotatable element, means operatively connecting said element and member whereby axial movement of said element relative to said member causes angular movement of said member relative to said element, and centrifugally responsive means operatively connected to said element'and said lmember for moving said element axially rst in one direction and then in the other direction relative to said member as the speed of rotation of the latter increases to thereby effect angular movement of said member relative to said element in both directions, said centrifugally responsive means comprising a pair of pivotally mounted and pivotally connected weights, the axis of said pivotal connection being one one side of a plane containing the axes of said mounting pivots when the apparatus is stationary and movable through said plane as the rotational speed increases.

3. Apparatus of the class described comprising two rotatable members adapted for angular movement relative to each other, and means for and so connected therewith that axial movement of said element effects relative angular movement of said members, and centrifugally responsive means for effecting said axial movement of said element, said last-named means comprising weight means pivotally mounted on one of said members, weight means ypivotally mounted on said element and means pivotally connecting the adjacent ends of said weight means, and resilient means for yieldingly lresisting movement of said Weight means in response to centrifugal forces and normally holding said weight means in a position Ysuch that the axis of said pivotal connection and the axis of rotation of said members` are on the same side of the plane containing said mounting axes so that the initial movement thereof in response to centrifugal forces effects axial movement of said element in onedirection k relative to said members and continued movement of the axis of said pivotal connection through said plane to the other side thereof effects axial movement of said element in the other direction relative to said members.

4. Apparatus or" the class described comprising two rotatable members, and torque-transmitting means operatively connecting said members including an element so connected with at least one or" said members that axial movement of said element eiiects angular movement of one of said members relative to the other of said members, and centrifugally responsive means including a plurality of links pivotally connected with each other and pivotally mounted on said element and one of said members, movement of said centriiugally responsive means in response to centrifugal forces being adapted to effect axial movement of said element in opposite directions relative to said members as the speed of rotation of said members increases from a given speed to a higher speed, the axis of said pivotal connection being on one side of a plane containing the pivotal mounting axes of said links when the apparatus is stationary and during rotation at said given speed and on the other side of said plane at a higher speed.

5. In appartus of the class described, a rotatable driving element, a rotatable driven element, and means drivably connecting said elements for limited movement relative to each other, said means comprising a centrifugally responsive weight member pivotally connected to one of said elements for rotation therewith and a connecting link pivotally connected to said member and to the other of said elements for rotation therewith so that the initial outward movement oi said weight member in response to centrifugal forces during rotation of said elements will effect relative movement of said elements in one direction and continued outward movement of said weight member in response to increased centrifugal force will eiTect relative movement of said elements in the opposite direction, the pivotal axis of the connection between said link and weight member being on one side of a plane containing the axes of the pivots connesting said weight member and link to said elements when the apparatus is stationary and during said initial movement of the weight member and movable outwardly and through said plane as the speed of rotation increases` 6. In apparatus of the class described, two rotatable members adapted for movement relative to each other, and means for drivably connecting said members including centrifugally responsive means comprisingY a plurality of pivotally connected links pivotally mounted on said members which eiect relative angular movement of said members rst in one direction and then in the opposite direction as the speed of rotation of said members increases, the pivotal mounting axes of said links being perpendicular to a plane containing the axis of rotation of said members and lines in said plane joining the mounting axis of each said link with the axis of the pivotal connection between said links forming an obtuse angle toward the axis of rotation of said members when the apparatus is stationary and forming an acute angle toward said axis of rotation when the links have been actuated by centrifugal force in response to rotational speed exceeding a predetermined value.

WALTER J. SPENGLER.

REFERENCES CTED The following references are of record in the file or" this patent:

UNTED STATES PATENTS Number Name Date 809,560 Graham et al Jan. 9, 1906 1,314,492 Aalborg Sept. 2, 1919 2,063,848 Meyer et al Dec. 8, 1936 2,071,641 Lunn Feb. 23, 1937 FOREIGN PATENTS Number Country Date 9,488 Great Britain of 1910 553,680 France of 1923 

